[Pw_forum] pwcond error: NAN value of transmission

[Paolo Giannozzi]

line 232 of PWCOND/src/compbs.f90, no quick fix (and not even a slow one,
unless somebody who knows the code has a look)

On Fri, Feb 9, 2018 at 4:26 PM, zhout2 <zhout2 at rpi.edu> wrote:

> Paolo,
>
> Thank you very much for your reply!
> Could you tell me which routine is involved, and is there a quick fix?
>
> Best wishes,
> Tianji
>
>
> On 2018-02-09 08:12, Paolo Giannozzi wrote:
> > On Fri, Jan 26, 2018 at 4:27 PM, Paolo Giannozzi
> > <p.giannozzi at gmail.com> wrote:
> >
> >> There are compiler options that catch invalid operations (e.g. -fpe0
> >> for Intel compiler)
> >
> > well, no, -fpe-all=0. There is actually a division by zero. Thank you
> > for reporting this
> >
> > Paolo
> >
> >
> >
> >> Paolo
> >>
> >> On Fri, Jan 26, 2018 at 6:09 AM, zhout2 <zhout2 at rpi.edu> wrote:
> >>
> >>> Dear QE community,
> >>>
> >>> I was using pwcond.x to do conductance calculations for metals,
> >>> which were successful in many systems, but failed in a few others,
> >>> in which cases the calculated transmission coefficients are -NAN,
> >>> as below:
> >>>
> >>> to transmit
> >>>  Band j to band i transmissions and reflections:
> >>>     j         i     |T_ij|^2    |R_ij|^2
> >>>
> >>>     1 -->     1        -NAN        -NAN
> >>>     1 -->     2        -NAN        -NAN
> >>>     ...
> >>>     1 -->     7        -NAN        -NAN
> >>>    Total T_j, R_j =       -NAN     -NAN
> >>>
> >>> As the calculations were not interrupted and no error message was
> >>> given, I am struggling to find the cause of error. Could someone
> >>> offer some insight?
> >>>
> >>> I have tried qe 5.1, 5.4 and 6.1, yet this error always appeared.
> >>> The crystal structure I used should be correct, because for some
> >>> other elements the calculations were successful. I'm attaching
> >>> both scf and pwcond files, though there was nothing wrong I could
> >>> notice with the scf step.
> >>>
> >>> Thanks and best regards,
> >>>
> >>> Tianji
> >>>
> >>> Tianji Zhou
> >>> Department of Materials Science and Engineering
> >>> Rensselaer Polytechnic Institute
> >>>
> >>> _______________________________________________
> >>> Pw_forum mailing list
> >>> Pw_forum at pwscf.org
> >>> http://pwscf.org/mailman/listinfo/pw_forum [1]
> >>
> >> --
> >>
> >> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
> >> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> >> Phone +39-0432-558216 [2], fax +39-0432-558222 [3]
> >
> > --
> >
> > Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
> > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> > Phone +39-0432-558216, fax +39-0432-558222
> >
> >
> >
> > Links:
> > ------
> > [1] http://pwscf.org/mailman/listinfo/pw_forum
> > [2] tel:+39%200432%20558216
> > [3] tel:+39%200432%20558222
> >
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://pwscf.org/mailman/listinfo/pw_forum
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
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